"""
Google Tasks API integration.
List, create, and complete tasks across all task lists.
"""
from googleapiclient.discovery import build
from core.google_auth import get_credentials

def _service():
    return build('tasks', 'v1', credentials=get_credentials())

def _get_default_list_id() -> str:
    svc = _service()
    lists = svc.tasklists().list(maxResults=1).execute()
    return lists['items'][0]['id']

def get_pending_tasks() -> list[dict]:
    """Return all incomplete tasks across all task lists."""
    svc = _service()
    tasklists = svc.tasklists().list(maxResults=10).execute()
    all_tasks = []
    for tl in tasklists.get('items', []):
        tasks = svc.tasks().list(
            tasklist=tl['id'], showCompleted=False, maxResults=50
        ).execute()
        for t in tasks.get('items', []):
            all_tasks.append({
                'id': t['id'],
                'tasklist_id': tl['id'],
                'title': t.get('title', ''),
                'due': t.get('due', ''),
                'notes': t.get('notes', ''),
                'list': tl['title'],
            })
    return all_tasks

def create_task(title: str, notes: str = None, due: str = None) -> dict:
    """Create a new task in the default task list."""
    svc = _service()
    list_id = _get_default_list_id()
    body = {'title': title}
    if notes:
        body['notes'] = notes
    if due:
        body['due'] = due
    return svc.tasks().insert(tasklist=list_id, body=body).execute()

def complete_task(tasklist_id: str, task_id: str) -> dict:
    """Mark a task as completed."""
    svc = _service()
    task = svc.tasks().get(tasklist=tasklist_id, task=task_id).execute()
    task['status'] = 'completed'
    return svc.tasks().update(tasklist=tasklist_id, task=task_id, body=task).execute()

def delete_task(tasklist_id: str, task_id: str):
    """Delete a task permanently."""
    _service().tasks().delete(tasklist=tasklist_id, task=task_id).execute()